Control valves for controlling the flow of high pressure fluids and/or gases in a process system are generally well known in the art. A control element such as a valve sleeve or valve plug or the like is typically disposed within the body of the valve in a position to obstruct or permit flow through the valve. The control element is typically operatively coupled to, for example, a sliding valve stem or a rotary valve stem, which in turn is coupled to a suitable valve actuator.
As is known, the valve stem is surrounded by valve packing. In many applications, the valve packing is disposed either in a packing box or in a valve bonnet. In any event, for a variety of reasons, a packing nut is provided in order to make necessary adjustments to the valve packing. Typically, the packing nut is a hex-head nut which is sized and shaped to be adjusted using a conventional wrench.
When larger diameter valve stems are used, a conventionally-shaped hex head packing nut may be difficult to adjust due to potential interference between a conventional wrench the various other valve components that surround the packing nut. In some applications, surrounding valve components present a clearance problem for the adjusting wrench even when the valve stem is a more conventional size.
Accordingly, it may be desirable to offer an alternative to the conventional packing nut.